lib/options: Throw error for options without a type

Makes all options rendered in the manual throw an error if they don't
have a type specified.

This is a follow-up to #76184

Co-Authored-By: Silvan Mosberger <contact@infinisil.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/options.nix b/lib/options.nix
index 627aac24d2f..9efc1249e58 100644
--- a/lib/options.nix
+++ b/lib/options.nix
@@ -231,7 +231,7 @@ rec {
             then true
             else opt.visible or true;
           readOnly = opt.readOnly or false;
-          type = opt.type.description or null;
+          type = opt.type.description or "unspecified";
         }
         // optionalAttrs (opt ? example) { example = scrubOptionValue opt.example; }
         // optionalAttrs (opt ? default) { default = scrubOptionValue opt.default; }